Focusing screen

Details Focusing screen Focusing screen

1980-11-24

1982-06-29

Adams, Russell E.

354166, 354219, G03B 1324

Patent

active

043369898

ABSTRACT:
This specification discloses a focusing screen adapted to be mounted in the range finder of a single lens reflex camera. A diffraction lattice is provided in the focus indicating part of the focusing screen. The diffraction lattice comprises a periodical arrangement of optically asymmetric unit structures in which +1st diffracted light and -1st diffracted light assume a color-complementing relation, and in the defocus (out of focus) condition, double images colored in two colors mutually having a color-complementing relation are produced. Further, this diffraction lattice structure is such that the period directions are opposite to each other in the upper and lower half areas of the focus indicating part and therefore, the manner of coloring is inversely symmetric in the upper and lower areas and color split occurs even at the bondary between these areas. These phenomena disappear when the focus condition is brought about.

REFERENCES:
patent: 3618498 (1971-11-01), Eppinger
patent: 4171890 (1979-10-01), Mizuki et al.

Affiliated with

Also associated with

Rating

Focusing screen does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Focusing screen, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Focusing screen will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2162929